Understanding Ramp Calculations
Calculating the correct ramp length ensures accessibility compliance, such as with ADA standards, for safe and usable ramps. This calculator uses vertical rise, desired slope, and a safety factor to account for construction tolerances.
The slope ratio (e.g., 1:12) means 1 inch of rise per 12 inches of ramp length. ADA recommends a 1:12 slope for accessibility, though steeper slopes (e.g., 1:8) may be allowed for short ramps.
Ramp Length Comparison by Rise and Slope
| Vertical Rise (in) | Slope Ratio | Ramp Length (ft) | Typical Use |
|---|---|---|---|
| 12 | 1:12 | 12 | Wheelchair ramp for small step |
| 24 | 1:12 | 24 | Standard entry ramp |
| 36 | 1:12 | 36 | Elevated platform access |
How to Use the Ramp Calculator
- Measure the vertical rise in inches (height the ramp needs to overcome).
- Enter the desired slope ratio (e.g., 1:12 for ADA compliance).
- Input a safety factor (typically 5-10%) for construction tolerances.
- Click "Calculate Ramp" to see the required ramp length and slope ratio.
Ramp Length Chart
Ramp length (ft) for different vertical rises (1:12 slope, 5% safety factor).
Frequently Asked Questions
What is the ADA-recommended slope for ramps?
The ADA recommends a 1:12 slope (1 inch rise per 12 inches of length) for accessibility ramps.
Why include a safety factor?
A 5-10% safety factor accounts for construction tolerances, uneven terrain, or minor design adjustments.